Contribution of Recently Measured Nuclear Data to Reactor Antineutrino Energy Spectra Predictions

Abstract The aim of this work is to study the impact of the inclusion of the recently measured β decay properties of the 102,104,105,106,107 Tc, 105 Mo, and 101 Nb nuclei in the calculation of the antineutrino (anti- ν ) energy spectra arising after the fissions of the four main fissile isotopes 235,238 U, and 239,241 Pu in PWRs. These β feeding probabilities, measured using the Total Absorption Technique (TAS) at the JYFL facility of Jyvaskyla, have been found to play a major role in the γ component of the decay heat for 239 Pu in the 4-3000 s range. Following the fission product summation method, the calculation was performed using the MCNP Utility Reactor Evolution code (MURE) coupled to the experimental spectra built from β decay properties of the fission products taken from evaluated databases. These latest TAS data are found to have a significant effect on the Pu isotope energy spectra and on the spectrum of 238 U showing the importance of their measurement for a better assessment of the reactor anti- ν energy spectrum, as well as importance for fundamental neutrino physics experiments and neutrino applied physics.